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Q: I need antifreeze and it looks like it's red, napa sold me green will it hurt to mix

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I was told not to mix colors due to it could cause an acid and eat at head gasket.

My car has 37000 miles.
My car has an automatic transmission.

Hello. The only antifreeze that should be used in your car is that specified in the owner’s manual and if not specified there, consult the OEM Factory Service Manual.

The consequences of mixing "different" coolants together - and different colors do signify different coolant chemistries - range from somewhat innocuous degradation in the service life of the corrosion packages in the coolant (thus necessitating more frequent drain intervals) to the creation of "gels" which could actually block the cooling system.

The chemical reactions involved are obviously way too detailed to get into here, but suffice it to say, whatever is added to the cooling system should be identical to that which is already in the vehicle, and hopefully what is already in the vehicle is that which is OEM specified. If not, drain everything, flush and refill.

Finally, I would not go by antifreeze manufacturer recommendations. I would instead consult the OEM specifications and instructions for antifreeze and follow those instructions.

Your question is an important one and shows you are on top of things and thinking ahead. If further maintenance concerns arise, or you need professional help with repairs, please contact YourMechanic. One of our mobile technicians can come to your home or office and top your vehicle off with the correct type of anti-freeze. Best of luck.

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